Community Forums

Avic77 · 05-12-2021, 10:43 AM

Hello everyone. Please help this confused newbie out!!! (Long explanation incoming)
My husband and I bought a Class C motorhome in September last year. We did lots of research and thought we were going in at least somewhat educated.
We took the MH to a tire shop and had the tires checked and got a new spare as the old spare was obviously dry rotted. Our first main outing we had a blowout on the drivers side back inside dually. Getting the tire change was a wakeup call on Roadside. The blow out also cracked our grey water tank and ripped our gas cap off! Got to our destination and picked up a new spare. Once home we took the RV to an RV shop and had full inspection, oil changes and 6 new tires put on.
We also ordered a TPMS.
We got the TPMS on the front tires and outside duallies and the passenger side inside dually (pain the the butt because there is NO hand room and the valves sit so close to the rim so we were not even sure we got it on good enough). We had a trip planned and decided once we got back we would go to the tire shop have them remove the outside dually and put the TPMS on the inner dually.
On our way home from our trip the TPMS goes off for the one inner dually we have the TPMS on saying its at 20PSI. We pull into a Lowes and check the tires. Everything looks good the moniter in still on it the tire looks fine (brand new tires with maybe 200 miles on them at this point). We think maybe we got a bad TPMS sensor.
We drive the remaining 60 miles home taking it easy going no more then 60 MPH.
Hubby decides we need to get the dually valves replaced with the long metal ones so I call the tire shop. They will do it but we need to order the dually valve kit. I have ordered that and it will be here next week.
Now I am reading all I can on dually tires and how to check air pressure and read about wacking the tire with a stick and listen for the difference in sound. So i go outside and whack the tires with a stick and sure enough the inner passenger dually SOUNDS DIFFERENT

Now I think we may have drove about 60 miles home with a low PSI on our inner passnger tire. So my questions are:

1) When the valves come in and I take the MH up to have them put on do I ask them to inspect that tire? Tell them we drove it 60 miles with it possibly being very low? Replace that tire? Inspect the outer tire on that side?

2) What tools do we need to have to be able to keep our tires in good condition and to check for problems? We have a TPMS but being newbies, knowing that our tire was brand new, and not seeing a problem we assumed maybe the sensor itself was bad instead of trusting it and assuming the tire had indeed lost pressure.

I am terrified of another blow out and I thought we would be good to go with 6 brand new tires!

Tires are becoming our most frustraiting and expensive lessonin RV life. Please give me a good old Motorhome Tire 101 tutorial!!!

hohenwald48 · 05-12-2021, 01:09 PM

Nothing specific about your particular situation, but there's an old aviation adage that says "trust your instruments".

I'd probably check the suspect tire with a tire gauge and see what's up. I would probably not drive on it until I did that.

On my rig, I can reach between the tires (class A with 22.5 tires). I've had class C's in the past and know that can be pretty difficult. I used to use an old flexible tire valve extension hose, screw it on the inside tire, check the pressure, add or remove air as needed then remove the extension hose.

Installing TPMS senders usually involved getting the tire rotated until the inner valve was in the right spot and then letting my wife stick her skinny arm up between the tires.

Charles L · 05-12-2021, 01:40 PM

Have the tire shop install the extensions. You should get the rubber insert (round or oval) that will hold the extension steady in the hole. This is important. The valve stems should be 180 degrees apart. The rims should have a pin that only aligns that way. Then ask the shop to air them up to your recommended psi and check with soapy water for leaks.

How do you know that you drove with only 20 psi on the tire? If this happens you should stop and check the pressure with a known accurate gage. TPMS should be verified with your own gage. Should be close within 1-2 psi of TPMS readings. Remember that your pressures will rise after driving. Always check your pressures cold and set them according the the load you are carrying. There is also a load/inflation chart online for your specific tires.

Gary RVRoamer · 05-12-2021, 01:54 PM

Definitely make sure that tire is holding air at the desired pressure. Other than that, I wouldn't worry too much. In theory you could have hurt the tire if it indeed was as low as 20 psi, but you don't know that it was (yet, anyway). And in practice the risk of having damaged it with low pressure is small. Not zero, but small. The best course of action would be to pull that tire and inspect it, but any damage would be internal and probably not obvious. And tire changers aren't exactly trained tire engineers either.

Maybe put that new spare on the dual and use the worrisome one as a spare? Might let you sleep better...

The whack-the-tire thing is at best an educated guess even for an experienced pro driver, and you aren't educated by any means.

Ray,IN · 05-12-2021, 05:17 PM

That low tire is considered "run-flat". it must be de-mounted and the inside inspected by a professional for damage.
To install inner dual TPMS sensors I use a 1' length of heater hose that the sensor fits into snugly, just take care not to over-tighten the sensor.
OTOH, my hand will fit between my duals when the inner stem is in the right positon' I can easily fit my hand and sensor between the duals to attach the sensor.

Avic77 · 05-12-2021, 07:22 PM

Thanks all.
Our tire issues are kind of freaking me out, maybe because of that first trip blow out. We ordered the Dually valve kit with the rubber donut thing to keep it from rubbing that I found mentioned in several posts on the forum. I will make sure the tire shop inspects that tire and its mate when they install the metal valve stems.
Again I am only assuming the tire is at the 20psi the tire monitor reported but it could be the monitor is faulty.
My husband is backing the office and will not get a chance to mess around with the RV till the weekend. The valves should be hear early next w3k and we will take it to the shop immediately.

MDM2 · 05-13-2021, 06:06 AM

If I read this correctly the same tire location had the issue the second time. If so, and the tire really did lose pressure, I would have a tire shop check the wheel and the surrounding area to make sure there isn’t something causing you to lose pressure.

Good luck

hohenwald48 · 05-14-2021, 05:42 AM

An inner dual with only 20psi will look fine in the Lowes parking lot as the outer tire will be holding the load so the inner won't look flat. However, driving 60 miles with the inner at 20psi will likely not only be harmful for that tire but for it's mate on the outside as it was carrying all the weight and was probably significantly overloaded.

Why would you assume the TPMS sender is faulty? Have you had problems with them before?

Since you had recently installed the TPMS sender on the inner tire, I'd be suspicious the sender was not properly installed and allowed the tire to leak down to 20psi. More likely than a bad sender.

One more thing. The person who installs new tires is usually not a "tire professional" but a kid working a temporary job.

Avic77 · 05-14-2021, 09:37 AM

No it's the other side from the 1st trip blow out

Quote:

Originally Posted by MDM2

If I read this correctly the same tire location had the issue the second time. If so, and the tire really did lose pressure, I would have a tire shop check the wheel and the surrounding area to make sure there isn’t something causing you to lose pressure.

Good luck

Avic77 · 05-14-2021, 10:10 AM

I agree I think the TPMS was not on good and allowed air to escape.

We will tell the tire place what happened and

We had no idea the tire would look ok even if it was low.
This is our first time with dual tires. We have read and watched videos and asked questions at the tire shop but i guess this is gonna be a hard lesson learned through as we go experience.

Quote:

Originally Posted by hohenwald48

An inner dual with only 20psi will look fine in the Lowes parking lot as the outer tire will be holding the load so the inner won't look flat. However, driving 60 miles with the inner at 20psi will likely not only be harmful for that tire but for it's mate on the outside as it was carrying all the weight and was probably significantly overloaded.

Why would you assume the TPMS sender is faulty? Have you had problems with them before?

Since you had recently installed the TPMS sender on the inner tire, I'd be suspicious the sender was not properly installed and allowed the tire to leak down to 20psi. More likely than a bad sender.

One more thing. The person who installs new tires is usually not a "tire professional" but a kid working a temporary job.

HarryStone · 05-16-2021, 04:55 PM

It can be a pain. On my class A, it has valve extenders, and the TPMS is on that. Haven't had a problem so far, and the extenders make is easy to remove and install the sensor.